The present invention relates to a method for the separation of phonograph record labels in an automatic, repeated operation, from a stack of phonograph record labels provided with center holes and stacked on a centering pin. The method involves bringing the successively outermost label, as considered in the feed-out direction, out of adhesive engagement with the adjacent label in the stack and presenting the outermost label in a preparatory position for being picked off from the stack. After pickoff the outermost label is conveyed to and delivered at a label-receiving station by means of a conveying means provided with suction means.
Previously, when separating a pliant sheet-like article from a stack of such articles and bringing said article into a position in which it is ready for separate transport to a working station where the article is applied to an intended surface the article has been removed from the stack by means of a collecting device which is brought into direct contact with the article lying outermost at the end of the stack. A disadvantage with such collecting or pick up devices is that, at least in the case of certain types of pliant sheet-like articles, it is difficult to prevent more than one article at a time from accompanying said device, thereby causing a high degree of wastage and uneconomical stoppages in production.
Particularly with respect to labels intended for phonograph records, the labels have hitherto been carried from a stack of such labels to a labelling station by means of one or more suction cups connected to a vacuum source, said suction cups being urged against the outermost label in the stack and then moved to said labelling station while maintaining a suction force in said cups. It is essential that the cups exert only that suction force required to remove a single label at a time from the stack of labels. If the suction force is excessively high then two or more labels may be removed at a time from the stack of labels, while on the other hand if the suction is excessively low then the label is liable to fall from the cup or the cup may fail to pick up a label from the stack. The percentage of phonograph records which must be rejected owing to the fact that a label has not been correctly applied thereto when using such suction cups is relatively high. As a result faulty labelling constitutes the major cause for rejection of phonograph records in the manufacture thereof using fully automatic apparatus.
It is also previously known, e.g. through the German patent specification No. 1,779,967, to suck out phonograph record labels from a stack of labels through a circular feed-out opening having a limiting surface which converges in the feed-out direction and which, as viewed in section, presents a toothed profile. The purpose of this construction is that the labels shall be urged to drag with their peripheral edges over the circular ridges thus formed in said profiled limiting surface in order to be shaken apart before being finally fed out. In practice, however, this method does not constitute any beneficial solution of the problem since the labels frequently have a tendency to adhere to each other at different places of the abutting surface, which consequently results in considerable incalculabilities in operation.